1. Field of the Invention
This invention relates to a manufacturing process for end fitting for eye joint fixed on a connection of metallic conduit, resin tube or the like relatively small in bore at 30 mm or below which is disposed and so used as feed passage for fuel, oil, air and so forth generally on automobiles or various types of machinery and apparatuses.
2. Description of the Prior Art
As illustrated by a manufacturing process in FIG. 3 (A) to (E), for example, a prior art process for such end fitting comprises forming a spherical head (12) on another end side of a cylindrical piece (11) cut to a necessary length through forging, drilling then a connection hole (13) therein on its one end side, forming next a flat plane (14) on one side of a peripheral surface of the head (12) through cutting and drilling a bolt hole (15) in the head orthogonally to the flat plane, further providing a flat plane (14') on a peripheral surface opposite to the flat plane (14) through cutting again, cutting and forming an annular recess groove (16) communicating with the connection hole (13) within the bolt hole (15) by means of a boring bar tool, and then deburring the cutting planes.
Further, that of using a bar material otherwise is known as disclosed in Japanese Patent Laid-Open No. 225843/1984. That is, a process for semimanufactured end fitting for eye joint proposed thereby comprises forming a metallic cylindrical piece into a hollow caplike member through punching, forming a head of the caplike member into a convexity through punching in the next stage, inserting a tube forming pin from an opening of the hollow caplike member and forming a tapered portion halfway of the hollow cap-like member, then forming the hollow caplike member into a spherical portion and a tubular portion having a small diametral part and a large diametral part by means of a punching die and a stepped pin.
However, in such prior art manufacturing process, since the process almost comprises cutting in the former, not only much time is required therefor to deteriorate considerably the productivity, but also a wastefulness is incurred on the material to cause a high manufacturing cost, and in the latter a series of forming covering another stage may involve a complexity of the equipment, and further a series of forming accompanying a plastic deformation due to a deep drawing at the hollow caplike member portion may inevitably lay down restrictions on use of the material, and thus a scope of application is limited accordingly.